Applied Physics Express (APEX) is a letters journal devoted solely to rapid dissemination of up-to-date and concise reports on new findings in applied physics. It is published daily online and monthly for the printed version. The motto of APEX is high scientific quality and prompt publication. APEX is a sister journal of the Japanese Journal of Applied Physics (JJAP) and is published by IOP Publishing Ltd on behalf of the Japan Society of Applied Physics (JSAP).
This publication is partially supported by a Grant-in-Aid for Publication of Scientific Research Results from the Japan Society for the Promotion of Science.
Number 7, July 2015 (071001-076601)
From 2014, APEX will be published by IOP Publishing on behalf of The Japan Society of Applied Physics. All submissions and refereeing will continue to be handled by the APEX Editorial Office at The Japan Society of Applied Physics. To submit a paper to APEX, please connect to the editorial web site.
In the last 30 days
Shiro Kaneko et al 2014 Appl. Phys. Express 7 035102
Silicene or germanene is a monolayer honeycomb lattice made of Si or Ge, similar to graphene made of C. In this work, we have assessed the performance potentials of silicene nanoribbon (SiNR), germanene nanoribbon (GeNR), and graphene nanoribbon (GNR), which all have a sufficient band gap to switch off, as field-effect transistor (FET) channel materials. We have demonstrated that, by comparing at the same band gap of ∼0.5 eV, the GNR FET maintains an advantage over SiNR or GeNR FETs under an ideal transport situation, but SiNR and GeNR are attractive channel materials for high-performance FETs as well.
Yongzhen Wu et al 2014 Appl. Phys. Express 7 052301
A uniform and pinhole-free hole-blocking layer is necessary for high-performance perovskite-based thin-film solar cells. In this study, we investigated the effect of nanoscale pinholes in compact TiO 2 layers on the device performance. Surface morphology and film resistance studies show that TiO 2 compact layers fabricated using atomic layer deposition (ALD) contain a much lower density of nanoscale pinholes than layers obtained by spin coating and spray pyrolysis methods. The ALD-based TiO 2 layer acts as an efficient hole-blocking layer in perovskite solar cells; it offers a large shunt resistance and enables a high power conversion efficiency of 12.56%.
M. Shoufie Ukhtary et al 2015 Appl. Phys. Express 8 055102
Undoped graphene is known to absorb 2.3% of visible light at a normal angle of incidence. In this paper, we theoretically demonstrate that the absorption of 10–100 GHz of an electromagnetic wave can be tuned from nearly 0 to 100% by varying the Fermi energy of graphene when the angle of incidence of the electromagnetic wave is kept within total internal reflection geometry. We calculate the absorption probability of the electromagnetic wave as a function of the Fermi energy of graphene and the angle of incidence of the wave. These results open up possibilities for the development of simple electromagnetic wave-switching devices operated by gate voltage.
Tohru Oka et al 2015 Appl. Phys. Express 8 054101
In this paper, we report on 1.2-kV-class vertical GaN-based trench metal–oxide–semiconductor field-effect transistors (MOSFETs) on a free-standing GaN substrate with a low specific on-resistance. A redesigned epitaxial layer structure following our previous work with a regular hexagonal trench gate layout enables us to reduce the specific on-resistance to as low as 1.8 mΩ·cm 2 while obtaining a sufficient blocking voltage for 1.2-kV-class operation. Normally-off operation with a threshold voltage of 3.5 V is also demonstrated. To the best of our knowledge, this is the first report on vertical GaN-based MOSFETs with a specific on-resistance of less than 2 mΩ·cm 2.
Tomo-o Terasawa and Koichiro Saiki 2015 Appl. Phys. Express 8 035101
To obtain a large-area single-crystal graphene, chemical vapor deposition (CVD) growth on Cu is considered the most promising. Recently, the surface oxygen on Cu has been found to suppress the nucleation of graphene. However, the effect of oxygen in the vapor phase was not elucidated sufficiently. Here, we investigate the effect of O 2 partial pressure ( P O2) on the CVD growth of graphene using radiation-mode optical microscopy. The nucleation density of graphene decreases monotonically with P O2, while its growth rate reaches a maximum at a certain pressure. Our results indicate that P O2 is an important parameter to optimize in the CVD growth of graphene.
Cyril Pernot et al 2010 Appl. Phys. Express 3 061004
We report on the fabrication and characterization of AlGaN-based deep ultraviolet light-emitting diodes (LEDs) with the emission wavelength ranging from 255 to 280 nm depending on the Al composition of the active region. The LEDs were flip-chip bonded and achieved external quantum efficiencies of over 3% for all investigated wavelengths. Under cw operation, an output power of more than 1 mW at 10 mA was demonstrated. A moth-eye structure was fabricated on the back side of the sapphire substrate, and on-wafer output power measurement indicated a 1.5-fold improvement of light extraction.
Kanako Shojiki et al 2015 Appl. Phys. Express 8 061005
N-polar (− c-plane) InGaN light-emitting diodes with emission wavelengths ranging from blue to green to red were fabricated on a c-plane sapphire substrate by metalorganic vapor phase epitaxy. The optimization of growth conditions for − c-plane InGaN/GaN multiple quantum wells was performed. As a result, the extension of the emission wavelength from 444 to 633 nm under a constant current of 20 mA was achieved by changing the growth temperature of quantum wells from 880 to 790 °C.
Kenji Ikeda et al 2015 Appl. Phys. Express 8 045501
We describe a new method for the selective crystallization of the metastable phase (α-form) of indomethacin. To obtain the α-form, we prepared a highly supersaturated solution and then introduced forcible nucleation techniques, namely, laser irradiation and magnetic stirring. When the laser irradiated near the side wall, the α-form crystallized within 24 h. The α-form crystals showed temporal stability for at least 8 months in air ambient at room temperature. We conclude that control of the laser irradiation focal point is an effective way of selectively crystallizing the metastable phase of indomethacin with temporal stability.
Toru Kinoshita et al 2015 Appl. Phys. Express 8 061003
Thick Si-doped AlN layers were homoepitaxially grown by hydride vapor phase epitaxy on AlN(0001) seed substrates. Following the removal of the seed substrate, an n-type AlN substrate with a carrier concentration of 2.4 × 10 14 cm −3 was obtained. Vertical Schottky barrier diodes were fabricated by depositing Ni/Au Schottky contacts on the N-polar surface of the substrate. High rectification with a turn-on voltage of approximately 2.2 V was observed. The ideality factor of the diode at room temperature was estimated to be ∼8. The reverse breakdown voltage, defined as the leakage current level of 10 −3 A/cm 2, ranged from 550 to 770 V.
Fang Nan et al 2015 Appl. Phys. Express 8 065203
The subthreshold transport properties in exfoliated MoS 2 FETs are reported. The temperature dependence of subthreshold characteristics in multilayered MoS 2 FETs behaves in the same way as that of conventional semiconductors, while conductance fluctuations and random telegraphic signals in the subthreshold region of I ds– V gs characteristics were observed much more frequently in monolayered FETs than in multilayered ones. This fact is understandable from the viewpoint of a three-dimensional to two-dimensional percolation transport process in MoS 2 with defects, which should be located in the MoS 2 layer or at the MoS 2/SiO 2 interface. Thus, it is suggested that few-layered MoS 2 FETs are more viable for practical applications from the viewpoint of suppressing defect-induced current fluctuations.
This cloud represents the 50 most popular PACS codes from the latest 250 coded articles for this journal. The larger the code the more times it occurs in those 250 articles. Click on a code to link to the articles in that category.
42.55.Px 42.65.Ky 42.60.Pk 42.15.Eq 07.57.Hm 06.30.Ft 42.60.Lh 42.65.Pc 42.30.Va 41.60.Cr 42.62.Cf 42.65.Tg 02.50.Fz 41.75.Fr 42.65.Jx 05.40.Ca 41.75.Jv 42.62.Be 42.55.Sa 42.70.Mp 42.30.Wb 42.25.Bs 33.50.Dq 07.60.Fs 07.55.-w 42.50.Gy 42.65.Wi 42.55.Rz 41.20.Jb 42.55.Wd 42.60.Jf 42.65.Re 42.70.Jk 31.15.ae 42.25.Ja 07.07.Df 31.15.ej 42.55.Xi 42.30.Lr 29.20.dg 42.25.Lc 31.15.A- 42.60.Da 29.25.Bx 07.55.Ge 07.85.Qe 42.40.Lx 42.55.Ye 42.50.Wk 42.50.Nn